engine troubles

So heres the story, the other day I was driving and the check engine light came on. I went home and scaned the codes. The codes that popped up were PO171 and PO174 which meant that the system was too lean. This could be due to a dirty MAF sensor but I am not sure.

Also sometimes when I start the VX, the engine will rev itself without me touching the gas, and it has stalled 3 times already. I wanted to post here to see if anyone has encountered a problem like this. Please let me know what you know or what you think the problem might be.

http://vehicross.info/forums/showthr...ighlight=P0171

If you are using an oiled air filter (eg, K&N) then that can screw up the MAF wires - beyond the point of cleaning.

Also, lean codes with an idle surge is often caused by leaking intake gaskets.

I had a reman engine installed by an Isuzu dealer 10k miles ago. I had the same issues and replaced almost all sensors only to find the intake gasket was crumbling. The dealer evidently over torqued the manifold. The gaskets are fragile plastic sandwiched between two thin metal plates. Take some starter fluid and spray around the gaskets where the lower intake bolts to the heads. Hopefully if theres a leak it's on the outside and the engine will rev if the intake gasket is leaking as it will suck in the starter fluid and rev up. If it's on the inside of the gasket under the intake it will not show this way. Mine did'nt act up until it was warm so if it doesn't work cold try letting it warm up.

Good Luck,:thumbup:

Mrcln1

I had a similar problem where my engine revved anywhere from 300 to 1500 rpms and then would rev down and die while I'm driving almost causing an accident.I took it in to the mechanic advising them it might be the IAC valve or the intake manifold gasket and thank God it turned out to be the IAC valve which was cheaper to repair.But I know the manifold gasket is next because I've already replaced the FPR last year.What's with this V-6??? I have never replaced a FPR , IAC valve or even a manifold gasket in my other cars that have much higher mileage.

IAC's can go bad in any car. In my 928, the equivalent part is buried under the entire intake manifold... it's 5 hours just to get at it, never mind putting it all back together!

FPRs are not commonly replaced, whihc is why I find it odd how many people on this site have replaced theirs, and some even advocate it as preventive maintenance. Also, many seem to have found that their problems didn't go away after replacing the FPR.

Intake gaskets can and do crack on any car, but especially on the VX because the initial torque spec for the manifold bolts was lowered after a few years, so that means they built them all (or most of them) at the factory that way, so many will crack and maybe leak after a while. Once it is replaced and torqued to the lower spec, they shoudl last a lot longer.

Good luck!

Vehigaz : Thanks for the reasurrance but I'm still disappointed that we're having these mechanical problems and in my case and probably others at such low mileage (36,500 miles).You would expect for these problems to occur at much higher mileage.But then again Isuzu has never been known for their reliability like Honda or Toyota and if we want this futuristic styling that's a real head turner than we'll have to just repair it or if you're going broke repairing it... sell it !!!

Thanks for all your help!
My dad took the VX to our mechanic yesterday and we found out that I do have a leak in my intake manifold gasket. My car only has 63,000 miles and I've only had it for 3 months and its already having problems. To top it off I have a decent size hole in my muffler, but because the muffler is in a shell, I have to order a whole new one instead of just giving it a patch job. Don't get me wrong, I love my car, I am even putting her in the car show in Halifax on Friday (Problems and all), but :_mecker: this is aggrivating!

All part of owning ANY car really. A gasket and a muffler are small change compared to any number of other failures you could get. ;)

While you're at it, you should hunt down a rare PV1 to replace the exhaust. ;)

Can anyone help my daugther & I find a new muffler? Either an OEM or PV1, she needs one A.S.A.P. Her VX is getting LOUD....:eek:

Thanks,
Dave...